which parts of “square” are further resolved into the “universals or components of every material thing: line, plane (in which a surface is contained), being bounded, angle, rectitude, and equality” (OL I.61; Hobbes 1981, 293). Then, those component parts are put back together (in synthesis), and by doing so learns that these parts are the “cause of square.”2
Applying these two paths of synthesis and analysis to the issue at hand, Hobbes says that one can proceed (in the order of one’s investigation) synthetically by beginning in First Philosophy with (already known) conceptions such as “space” and “motion simpliciter” and working through geometry, physics, and morals, adding the relevant concepts proper to each discipline along the way, until coming to the principles of politics (OL I.63–5; Hobbes 1981, 297–301). Alternatively, Hobbes claims that “those who have not learned the earlier part of philosophy … can nevertheless come to the principles of civil philosophy by the analytic method” (OL I.65; Hobbes 1981, 301). How does this analysis work for such individuals? Hobbes suggests that whenever the everyday person without prior philosophical training is presented with a question (such as “whether such and such an action is just or unjust”), they are capable of resolving or analyzing the conceptions in that question into component parts. This analysis will break apart “unjust” into “fact” and “against the laws” and by continuing to resolve these conceptions will arrive at “the fact that the appetites men and the motions of their minds are such that they will wage war against each other unless controlled by some power” (OL I.66; Hobbes 1981, 303).
Hobbes optimistically claims that once the everyday person arrives at this knowledge of humans in their natural state simply by analysis from a question like “is X just or unjust” that they will be able to determine whether any possible action is just or unjust “by composition” (OL I.66; Hobbes 1981, 303). Thus, the everyday person will engage in both analysis and synthesis. The picture that emerges is that by either means one may arrive at the principles of civil philosophy, and that either path (in Figure 4.2) is a legitimate means of doing so.
Figure 4.2 Orders of knowing to arrive at civil philosophy.
Against the portrayal of Hobbes as a reductionist or deductivist, Hobbes’s claims about these two orders of knowing eschews reduction or an attempted strict derivation from one “level” to another. On the first path of synthesis (the left inverted pyramid in Figure 4.2), one begins in First Philosophy and clarifies conceptions like “space,” “place,” and “motion simpliciter.” These conceptions are then used within geometry when making figures such as lines and squares. Those geometrical figures incorporate the conceptions from First Philosophy but are in no way reducible to them; indeed, geometry adds to these earlier conceptions as it makes figures and determines their natures. Continuing upward, as it were, geometry will be used within physics but physics must add to geometry when it treats features of actual bodies in nature, such as “the action of shining [bodies]” (Hobbes 1973 [1642–1643], 106; 1976 [1642–1643], 24–5). This “adding to” activity, as has been discussed already, constitutes synthesis for Hobbes.
However, Hobbes held that an alternative order of knowing from the everyday experience of one’s own mind to the principles of civil philosophy was an equally legitimate way to arrive at the principles of civil philosophy. In this case (the right inverted pyramid in Figure 4.2), one subtracts or resolves the questions made salient in one’s personal experience, such as “is X just or unjust?” by considering one’s conception of “just” and examining its component parts. This subtracting or resolving will continue until reaching a claim about humans in their natural state. Then moving from that claim – in synthesis – one can determine whether any action would be just or unjust.3 Hobbes does not assume that those moving from everyday experience to the state of nature have stopped in an inferior place compared to the starting point for those beginning in First Philosophy. In other words, he does not claim that ideally there should be a further reduction; these two orders are simply different means for reaching the same result.
The following section and the next turn away from Hobbes’s statements about how the parts of his philosophy fit together and focus instead on Hobbes’s actual practice of providing explanations. Scholarly attention has mostly been directed toward the former, but in actual practice we find Hobbes weaving together principles from geometry into explanations that simultaneously rely upon everyday experience and geometry. What could allow him to do this, assuming his statements and practice are consistent with one another? Before turning toward Hobbes’s practice, I will first discuss briefly what Hobbes describes in De homine as “true physics” (Hobbes 1994b [1658], 42; OL II.93).
The starting point for considering what Hobbes calls “true physics” is a division that he makes in De corpore VI.1 between knowing with certainty (scientia) and more mundane forms of knowing (cognitio):
We are said to know [scire] some effect when we know what its causes are, in what subject they are, in what subject they introduce the effect and how they do it. Therefore, this is the knowledge [scientia] τοῦ διότι or of causes. All other knowledge [cognitio], which is called τοῦ ὅτι, is either sense experience or imagination remaining in sense experience or memory.
(OL I.58–9; Hobbes 1981, 287–9)
Essentially, Hobbes divides all human knowledge into two parts: scientia, for which we possess knowledge of the causes (i.e., knowledge of the “why”), and cognitio, for which we have mere sense experience or the remnants of sense experiences in the form of imaginations (i.e., knowledge of the “that”). These two parts provide different levels of certainty to knowers. Since scientia is knowledge of the actual causes of some effect, knowers possess certainty concerning how that effect came to be.4
How could Hobbes, with his reliance upon sense as the source for all ideas (e.g., 2012, 22; 1651, 3), hope to lay claim to epistemic certainty? The move he makes is that humans possess scientia only in cases where they act as the maker of some effect, and so geometry and civil philosophy are the only contexts in which this is possible, a claim Hobbes makes in Six Lessons (EW VII.184) and in De homine (OL II.93–4; Hobbes 1994b [1658], 41). In both geometry and civil philosophy, human knowers begin from abstract objects, such as bodies in imagination considered as geometrical points or human bodies in imagination considered as being in their natural state. There are no such entities in the natural world, as Hobbes’s criticisms of Euclid make clear (e.g., EW VII.202), but humans can create them by considering their imaginations in certain ways. Human knowers next move around those abstract objects in their imagination and consider the effects of combinations of those bodies and the motions of those bodies. In doing this, they create some effect, such as “lines and figures” in geometry (EW VII.184) or “the principles – that is, the causes of justice (namely laws and covenants) …” in civil philosophy (OL II.94; Hobbes 1994b [1658], 42). They possess scientia of those effects because they, as makers, brought them about as they actively constructed them.
The second part of Hobbesian human knowledge – cognitio – provides the basis for nearly all human decisions. When I hear a sound outside at night, suspect that sound is a coyote, and decide to check the security of the chicken coop, this results in a conjecture. The conjecture I make is only as good as my prior experiences: those of nocturnal animal noises, my comparison between the current sound and those in the past, and the linkages related to what happened to the coop following my hearing of past sounds from coyotes (stored as “Transitions from one imagination to another …” from past sense experiences; see Leviathan 3; 2012, 38; 1651, 8). The likelihood that my conjecture “The hens are about to be eaten!” will be accurate will thus depend upon the quantity and quality of those past experiences, what Hobbes describes in Leviathan 3 as “Foresight, and Prudence, or Providence; and sometimes Wisdome” (2012,